Auto pilot landings have been well developed for years. Currently they're only used when visibility is low but they can be used at any time. So for a circular runway, auto-landings would have to be the norm.

Interesting concept. I did not see any mention of the safety zone required around the runway. If something goes wrong During landing would think that a plane would go outside of the runway due to centripetal force. Using present straight runways the plane stands a chance of staying on or near the runway improving access for emergency services.
I am not an expert so wiser souls please feel free to correct me.

Circular runways are for helicopters, not for giant airliners that land
at over 100 MPH or 160 KPH, and as mentioned by Kendo what about the crosswind factors and
other mechanical failures that aircraft still have today, this is a hair brained concept at best.
Geezer

Pluto is my favorite planet!, especially now that we all can see close up
pictures of it.